Electronics

  2010 SEP 8 - (VerticalNews.com) -- "The radio over fiber system that transmits different signals simultaneously for 30-GHz wireless and 1.25-Gb/s wired network is proposed," investigators in Seoul, South Korea report.

  "One sub-carrier of a double-sideband wireless signal is re-modulated by injection-locking technique using a Fabry-Perot laser diode (FP LD) to generate a wired signal. Since the condition of injection-locking varies with changes of the input optical power and the injected current of the FP LD, the BER performance of the wired signal is investigated according to the modulation depth of both the wireless and wired signals, respectively," wrote H.S. Kim and colleagues, Yonsei University ...read more

  2010 SEP 8 - (VerticalNews.com) -- "The optical characteristics of ultraviolet-violet InGaN laser diodes with different numbers of quantum wells under normal and reversed polarizations are numerically investigated," scientists in Changhua, Taiwan report.

  "For the laser structures under normal polarization, the lowest threshold current is obtained when the number of quantum wells is two in the spectral range of 380-408 nm. For the laser structures under reversed polarization, the single quantum-well laser structure possesses the lowest threshold current," wrote Y.K. Kuo and colleagues ...read more

  2010 AUG 25 - (VerticalNews.com) -- According to a study from People's Republic of China, "This paper predicts that bright-dark self-coupled vector solitons are possible in biased two-photon photovoltaic photorefractive crystals under steady-state conditions."

  "The solutions of these vector solitons can be determined by use of simple numerical integration procedures. When the photovoltaic effect is neglectable, these vector solitons are bright-dark vector screening solitons," wrote Q.C. Jiang and colleagues ...read more